Puffed snacks made from ingredients such as potato, corn, rice flour and legumes have always been widely loved for their delicious taste and light, crisp texture. These snacks are usually made by adding a puffing agent to the ingredients and deep-frying them in cooking oil to puff them up.
However, puffed snacks made by this method contain a lot of oil. This makes them high in fat and calories, potentially causing health problems if too many are consumed. This method is also at odds with the recent increase in health-consciousness.
In order to resolve the health issues associated with such puffed snacks, non-frying methods have been proposed as an alternative to deep-frying in oil. As the name suggests, non-frying methods produce the same crisp, light texture without frying the snacks in oil.
One such method is to puff up pellets of ingredients by heat-pressing them. This method makes it possible to maintain the same unique crisp, light texture of puffed snacks, without the high fat and calorie content caused by frying in oil.
The device for puffing snacks detailed in Patent Document 1 proposes one device to be used in this non-frying method in which ingredients are puffed by heat-pressing. This device heat-presses ingredients between a pair of opposing rollers and then instantaneously returns them to ordinary temperature and pressure. This causes the water in the ingredients to vaporize instantaneously, puffing the snacks.
In the invention detailed in Patent Document 1, the pair of rollers are supplied with oil that has been heated to around 220° C. (428° F.) with a heater. This oil moves between the rollers, maintaining a high temperature.